How to calculate user licences ?

Hello, I have to calculate the number of Informix user-licences we need for our office. I have to now for SE-7.23 and IDS 7.3 on HPUX10.20. The problem is to know what happens if I try to connect with more then we bought ? This time we use a 64-user database but we doesn't really have so much current users. Our environment: We'll use our ESQL-C programs in telnet sessions from MS-Windows clients. There are multiple connects from one client possible. But the user really can use one of it at the same time. But we need it to switch between the applications and I doesn't know how many connections we will get. Our sales-office told us to buy one licence for every task. Do we really need it ? How many system-connections I have to add ? The onstat -u tells me about five current active userthreads without any user/program connection.(what does the total-number mean ?) Perhaps anyone can tell me what I have to know ? :-) regards Dirk Niemeier